What should the normal oxygen saturation level (SaO2) be in arterial blood?

• A. 85-95%
• B. 90-100%
• C. 95-100%
• D. 100-105%

Answer: (C)

The normal oxygen saturation level (SaO2) in arterial blood should be between 95-100%. This range signifies that the hemoglobin in the blood is effectively saturated with oxygen, ensuring that adequate oxygen is being delivered to the body’s tissues. When SaO2 levels are at or above 95%, it indicates that there is sufficient oxygen available for metabolic processes, which is crucial for maintaining cellular function and overall health.

Levels below this threshold can indicate hypoxemia or inadequate oxygenation, while values above 100% are physiologically impossible in the context of arterial blood saturation, as hemoglobin cannot carry more oxygen than its maximum capacity. Maintaining an SaO2 within the normal range is vital for preventing adverse health effects associated with both hypoxia and hyperoxia. Therefore, identifying the correct normal range is fundamental in pulmonary practice and patient assessment.